The present invention is directed to bicycles and, more particularly, to a bicycle power supply with a discharge function.
Some recent bicycles have been equipped with electronically controllable electrical components such as derailleurs, suspension devices, displays, etc., along with the electrical controllers for such components. A well-known example of this technology is an automatic bicycle transmission that uses a speed sensor to automatically change gears according to bicycle speed. In all cases, a power supply is required to supply electricity to the various electronic components. Sometimes batteries are used for such power supplies. However, batteries need to be replaced when their electricity is consumed, and such replacement places undesirable burdens on the rider. Furthermore, the electrical components may suddenly stop operating when the batteries are depleted, which can be very problematic.
To avoid the above problems, some systems use a rechargeable battery as the power supply, wherein the rechargeable battery may be recharged using an alternating current generator mounted to the bicycle. Such a system is shown in JP 2001-245475. In this system, a rectifier converts current from an alternating current generator to direct current, and the direct current is used to charge a capacitor that functions as a battery unit. The capacitors typically comprise electrolytic or double layer capacitors with relatively large capacities. Power from the capacitor then may be used to operate the various electrical components mounted on the bicycle.
While the use of rechargeable batteries solves some of the problems of single-use batteries, they still have some disadvantages. For example, since bicycles are used outdoors, the temperature of the power supply may increase dramatically when the bicycle is parked under exposure to direct sunlight, and such temperatures may shorten the life of the battery. In order to avoid this problem, protective measures have been taken such as covering the battery with insulating material. However, this increases the size of the battery, thus making it more difficult to install the battery onto the bicycle.